A quasi-experimental pretest-posttest control group design was employed.

Methods:

Forty-eight adults 65 years of age and older with MCI (experimental, n = 24; control, n = 24) who were living in care facilities in Gyeong-gi-do, Korea, were recruited. Multivitamin supplements as experimental treatment consisted of vitamin B6, B12, and folic acid. Multivitamin supplements were taken at a dosage of one pill every day for 12 weeks through the oral route. Measures were Mini Mental State Examination-Korean, serum homocysteine level, and Geriatric Depression Scale Short Form Korea Version. Collected data were analyzed using SPSS version 21.0 statistical software (SPSS Inc., Chicago, IL, USA).